Louvered roof structures are a popular option for conditioning outdoor spaces. Such roof structures generally include a series of closely-spaced louvers (in some cases alternatively called slats or blades) that can be collectively reoriented to change conditions of a space. For example, a series of louvers oriented together so that each is pointed upward may provide gaps between the louver blades through which sunlight or airflow can pass. When shade is desired, the louvers can be moved so that they are positioned generally perpendicular to the sun or other source of light or weather conditions. Such arrangements may allow for a great deal of versatility in adjusting a roof of a patio or other outdoor shelter to accommodate different weather conditions. However, many louver systems are not water tight when the louvers are closed against one another. This can cause problems, such as putting furniture or guests under a louvered roof structure at risk of getting wet in rainy conditions.